/* hv.c * * Copyright (C) 1991, 1992, 1993, 1994, 1995, 1996, 1997, 1998, 1999, * 2000, 2001, 2002, 2003, 2004, by Larry Wall and others * * You may distribute under the terms of either the GNU General Public * License or the Artistic License, as specified in the README file. * */ /* * "I sit beside the fire and think of all that I have seen." --Bilbo */ /* =head1 Hash Manipulation Functions A HV structure represents a Perl hash. It consists mainly of an array of pointers, each of which points to a linked list of HE structures. The array is indexed by the hash function of the key, so each linked list represents all the hash entries with the same hash value. Each HE contains a pointer to the actual value, plus a pointer to a HEK structure which holds the key and hash value. =cut */ #include "EXTERN.h" #define PERL_IN_HV_C #define PERL_HASH_INTERNAL_ACCESS #include "perl.h" #define HV_MAX_LENGTH_BEFORE_SPLIT 14 STATIC HE* S_new_he(pTHX) { HE* he; LOCK_SV_MUTEX; if (!PL_he_root) more_he(); he = PL_he_root; PL_he_root = HeNEXT(he); UNLOCK_SV_MUTEX; return he; } STATIC void S_del_he(pTHX_ HE *p) { LOCK_SV_MUTEX; HeNEXT(p) = (HE*)PL_he_root; PL_he_root = p; UNLOCK_SV_MUTEX; } STATIC void S_more_he(pTHX) { register HE* he; register HE* heend; XPV *ptr; New(54, ptr, 1008/sizeof(XPV), XPV); ptr->xpv_pv = (char*)PL_he_arenaroot; PL_he_arenaroot = ptr; he = (HE*)ptr; heend = &he[1008 / sizeof(HE) - 1]; PL_he_root = ++he; while (he < heend) { HeNEXT(he) = (HE*)(he + 1); he++; } HeNEXT(he) = 0; } #ifdef PURIFY #define new_HE() (HE*)safemalloc(sizeof(HE)) #define del_HE(p) safefree((char*)p) #else #define new_HE() new_he() #define del_HE(p) del_he(p) #endif STATIC HEK * S_save_hek_flags(pTHX_ const char *str, I32 len, U32 hash, int flags) { int flags_masked = flags & HVhek_MASK; char *k; register HEK *hek; New(54, k, HEK_BASESIZE + len + 2, char); hek = (HEK*)k; Copy(str, HEK_KEY(hek), len, char); HEK_KEY(hek)[len] = 0; HEK_LEN(hek) = len; HEK_HASH(hek) = hash; HEK_FLAGS(hek) = (unsigned char)flags_masked; if (flags & HVhek_FREEKEY) Safefree(str); return hek; } /* free the pool of temporary HE/HEK pairs retunrned by hv_fetch_ent * for tied hashes */ void Perl_free_tied_hv_pool(pTHX) { HE *ohe; HE *he = PL_hv_fetch_ent_mh; while (he) { Safefree(HeKEY_hek(he)); ohe = he; he = HeNEXT(he); del_HE(ohe); } PL_hv_fetch_ent_mh = Nullhe; } #if defined(USE_ITHREADS) HE * Perl_he_dup(pTHX_ HE *e, bool shared, CLONE_PARAMS* param) { HE *ret; if (!e) return Nullhe; /* look for it in the table first */ ret = (HE*)ptr_table_fetch(PL_ptr_table, e); if (ret) return ret; /* create anew and remember what it is */ ret = new_HE(); ptr_table_store(PL_ptr_table, e, ret); HeNEXT(ret) = he_dup(HeNEXT(e),shared, param); if (HeKLEN(e) == HEf_SVKEY) { char *k; New(54, k, HEK_BASESIZE + sizeof(SV*), char); HeKEY_hek(ret) = (HEK*)k; HeKEY_sv(ret) = SvREFCNT_inc(sv_dup(HeKEY_sv(e), param)); } else if (shared) HeKEY_hek(ret) = share_hek_flags(HeKEY(e), HeKLEN(e), HeHASH(e), HeKFLAGS(e)); else HeKEY_hek(ret) = save_hek_flags(HeKEY(e), HeKLEN(e), HeHASH(e), HeKFLAGS(e)); HeVAL(ret) = SvREFCNT_inc(sv_dup(HeVAL(e), param)); return ret; } #endif /* USE_ITHREADS */ static void S_hv_notallowed(pTHX_ int flags, const char *key, I32 klen, const char *msg) { SV *sv = sv_newmortal(), *esv = sv_newmortal(); if (!(flags & HVhek_FREEKEY)) { sv_setpvn(sv, key, klen); } else { /* Need to free saved eventually assign to mortal SV */ /* XXX is this line an error ???: SV *sv = sv_newmortal(); */ sv_usepvn(sv, (char *) key, klen); } if (flags & HVhek_UTF8) { SvUTF8_on(sv); } Perl_sv_setpvf(aTHX_ esv, "Attempt to %s a restricted hash", msg); Perl_croak(aTHX_ SvPVX(esv), sv); } /* (klen == HEf_SVKEY) is special for MAGICAL hv entries, meaning key slot * contains an SV* */ #define HV_FETCH_ISSTORE 0x01 #define HV_FETCH_ISEXISTS 0x02 #define HV_FETCH_LVALUE 0x04 #define HV_FETCH_JUST_SV 0x08 /* =for apidoc hv_store Stores an SV in a hash. The hash key is specified as C and C is the length of the key. The C parameter is the precomputed hash value; if it is zero then Perl will compute it. The return value will be NULL if the operation failed or if the value did not need to be actually stored within the hash (as in the case of tied hashes). Otherwise it can be dereferenced to get the original C. Note that the caller is responsible for suitably incrementing the reference count of C before the call, and decrementing it if the function returned NULL. Effectively a successful hv_store takes ownership of one reference to C. This is usually what you want; a newly created SV has a reference count of one, so if all your code does is create SVs then store them in a hash, hv_store will own the only reference to the new SV, and your code doesn't need to do anything further to tidy up. hv_store is not implemented as a call to hv_store_ent, and does not create a temporary SV for the key, so if your key data is not already in SV form then use hv_store in preference to hv_store_ent. See L for more information on how to use this function on tied hashes. =cut */ SV** Perl_hv_store(pTHX_ HV *hv, const char *key, I32 klen_i32, SV *val, U32 hash) { HE *hek; STRLEN klen; int flags; if (klen_i32 < 0) { klen = -klen_i32; flags = HVhek_UTF8; } else { klen = klen_i32; flags = 0; } hek = hv_fetch_common (hv, NULL, key, klen, flags, (HV_FETCH_ISSTORE|HV_FETCH_JUST_SV), val, hash); return hek ? &HeVAL(hek) : NULL; } SV** Perl_hv_store_flags(pTHX_ HV *hv, const char *key, I32 klen, SV *val, register U32 hash, int flags) { HE *hek = hv_fetch_common (hv, NULL, key, klen, flags, (HV_FETCH_ISSTORE|HV_FETCH_JUST_SV), val, hash); return hek ? &HeVAL(hek) : NULL; } /* =for apidoc hv_store_ent Stores C in a hash. The hash key is specified as C. The C parameter is the precomputed hash value; if it is zero then Perl will compute it. The return value is the new hash entry so created. It will be NULL if the operation failed or if the value did not need to be actually stored within the hash (as in the case of tied hashes). Otherwise the contents of the return value can be accessed using the C macros described here. Note that the caller is responsible for suitably incrementing the reference count of C before the call, and decrementing it if the function returned NULL. Effectively a successful hv_store_ent takes ownership of one reference to C. This is usually what you want; a newly created SV has a reference count of one, so if all your code does is create SVs then store them in a hash, hv_store will own the only reference to the new SV, and your code doesn't need to do anything further to tidy up. Note that hv_store_ent only reads the C; unlike C it does not take ownership of it, so maintaining the correct reference count on C is entirely the caller's responsibility. hv_store is not implemented as a call to hv_store_ent, and does not create a temporary SV for the key, so if your key data is not already in SV form then use hv_store in preference to hv_store_ent. See L for more information on how to use this function on tied hashes. =cut */ HE * Perl_hv_store_ent(pTHX_ HV *hv, SV *keysv, SV *val, U32 hash) { return hv_fetch_common(hv, keysv, NULL, 0, 0, HV_FETCH_ISSTORE, val, hash); } /* =for apidoc hv_exists Returns a boolean indicating whether the specified hash key exists. The C is the length of the key. =cut */ bool Perl_hv_exists(pTHX_ HV *hv, const char *key, I32 klen_i32) { STRLEN klen; int flags; if (klen_i32 < 0) { klen = -klen_i32; flags = HVhek_UTF8; } else { klen = klen_i32; flags = 0; } return hv_fetch_common(hv, NULL, key, klen, flags, HV_FETCH_ISEXISTS, 0, 0) ? TRUE : FALSE; } /* =for apidoc hv_fetch Returns the SV which corresponds to the specified key in the hash. The C is the length of the key. If C is set then the fetch will be part of a store. Check that the return value is non-null before dereferencing it to an C. See L for more information on how to use this function on tied hashes. =cut */ SV** Perl_hv_fetch(pTHX_ HV *hv, const char *key, I32 klen_i32, I32 lval) { HE *hek; STRLEN klen; int flags; if (klen_i32 < 0) { klen = -klen_i32; flags = HVhek_UTF8; } else { klen = klen_i32; flags = 0; } hek = hv_fetch_common (hv, NULL, key, klen, flags, HV_FETCH_JUST_SV | (lval ? HV_FETCH_LVALUE : 0), Nullsv, 0); return hek ? &HeVAL(hek) : NULL; } /* =for apidoc hv_exists_ent Returns a boolean indicating whether the specified hash key exists. C can be a valid precomputed hash value, or 0 to ask for it to be computed. =cut */ bool Perl_hv_exists_ent(pTHX_ HV *hv, SV *keysv, U32 hash) { return hv_fetch_common(hv, keysv, NULL, 0, 0, HV_FETCH_ISEXISTS, 0, hash) ? TRUE : FALSE; } /* returns an HE * structure with the all fields set */ /* note that hent_val will be a mortal sv for MAGICAL hashes */ /* =for apidoc hv_fetch_ent Returns the hash entry which corresponds to the specified key in the hash. C must be a valid precomputed hash number for the given C, or 0 if you want the function to compute it. IF C is set then the fetch will be part of a store. Make sure the return value is non-null before accessing it. The return value when C is a tied hash is a pointer to a static location, so be sure to make a copy of the structure if you need to store it somewhere. See L for more information on how to use this function on tied hashes. =cut */ HE * Perl_hv_fetch_ent(pTHX_ HV *hv, SV *keysv, I32 lval, register U32 hash) { return hv_fetch_common(hv, keysv, NULL, 0, 0, (lval ? HV_FETCH_LVALUE : 0), Nullsv, hash); } STATIC HE * S_hv_fetch_common(pTHX_ HV *hv, SV *keysv, const char *key, STRLEN klen, int flags, int action, SV *val, register U32 hash) { XPVHV* xhv; U32 n_links; HE *entry; HE **oentry; SV *sv; bool is_utf8; int masked_flags; if (!hv) return 0; if (keysv) { if (flags & HVhek_FREEKEY) Safefree(key); key = SvPV(keysv, klen); flags = 0; is_utf8 = (SvUTF8(keysv) != 0); } else { is_utf8 = ((flags & HVhek_UTF8) ? TRUE : FALSE); } xhv = (XPVHV*)SvANY(hv); if (SvMAGICAL(hv)) { if (SvRMAGICAL(hv) && !(action & (HV_FETCH_ISSTORE|HV_FETCH_ISEXISTS))) { if (mg_find((SV*)hv, PERL_MAGIC_tied) || SvGMAGICAL((SV*)hv)) { sv = sv_newmortal(); /* XXX should be able to skimp on the HE/HEK here when HV_FETCH_JUST_SV is true. */ if (!keysv) { keysv = newSVpvn(key, klen); if (is_utf8) { SvUTF8_on(keysv); } } else { keysv = newSVsv(keysv); } mg_copy((SV*)hv, sv, (char *)keysv, HEf_SVKEY); /* grab a fake HE/HEK pair from the pool or make a new one */ entry = PL_hv_fetch_ent_mh; if (entry) PL_hv_fetch_ent_mh = HeNEXT(entry); else { char *k; entry = new_HE(); New(54, k, HEK_BASESIZE + sizeof(SV*), char); HeKEY_hek(entry) = (HEK*)k; } HeNEXT(entry) = Nullhe; HeSVKEY_set(entry, keysv); HeVAL(entry) = sv; sv_upgrade(sv, SVt_PVLV); LvTYPE(sv) = 'T'; /* so we can free entry when freeing sv */ LvTARG(sv) = (SV*)entry; /* XXX remove at some point? */ if (flags & HVhek_FREEKEY) Safefree(key); return entry; } #ifdef ENV_IS_CASELESS else if (mg_find((SV*)hv, PERL_MAGIC_env)) { U32 i; for (i = 0; i < klen; ++i) if (isLOWER(key[i])) { /* Would be nice if we had a routine to do the copy and upercase in a single pass through. */ char *nkey = strupr(savepvn(key,klen)); /* Note that this fetch is for nkey (the uppercased key) whereas the store is for key (the original) */ entry = hv_fetch_common(hv, Nullsv, nkey, klen, HVhek_FREEKEY, /* free nkey */ 0 /* non-LVAL fetch */, Nullsv /* no value */, 0 /* compute hash */); if (!entry && (action & HV_FETCH_LVALUE)) { /* This call will free key if necessary. Do it this way to encourage compiler to tail call optimise. */ entry = hv_fetch_common(hv, keysv, key, klen, flags, HV_FETCH_ISSTORE, NEWSV(61,0), hash); } else { if (flags & HVhek_FREEKEY) Safefree(key); } return entry; } } #endif } /* ISFETCH */ else if (SvRMAGICAL(hv) && (action & HV_FETCH_ISEXISTS)) { if (mg_find((SV*)hv, PERL_MAGIC_tied) || SvGMAGICAL((SV*)hv)) { SV* svret; /* I don't understand why hv_exists_ent has svret and sv, whereas hv_exists only had one. */ svret = sv_newmortal(); sv = sv_newmortal(); if (keysv || is_utf8) { if (!keysv) { keysv = newSVpvn(key, klen); SvUTF8_on(keysv); } else { keysv = newSVsv(keysv); } mg_copy((SV*)hv, sv, (char *)sv_2mortal(keysv), HEf_SVKEY); } else { mg_copy((SV*)hv, sv, key, klen); } if (flags & HVhek_FREEKEY) Safefree(key); magic_existspack(svret, mg_find(sv, PERL_MAGIC_tiedelem)); /* This cast somewhat evil, but I'm merely using NULL/ not NULL to return the boolean exists. And I know hv is not NULL. */ return SvTRUE(svret) ? (HE *)hv : NULL; } #ifdef ENV_IS_CASELESS else if (mg_find((SV*)hv, PERL_MAGIC_env)) { /* XXX This code isn't UTF8 clean. */ const char *keysave = key; /* Will need to free this, so set FREEKEY flag. */ key = savepvn(key,klen); key = (const char*)strupr((char*)key); is_utf8 = 0; hash = 0; keysv = 0; if (flags & HVhek_FREEKEY) { Safefree(keysave); } flags |= HVhek_FREEKEY; } #endif } /* ISEXISTS */ else if (action & HV_FETCH_ISSTORE) { bool needs_copy; bool needs_store; hv_magic_check (hv, &needs_copy, &needs_store); if (needs_copy) { bool save_taint = PL_tainted; if (keysv || is_utf8) { if (!keysv) { keysv = newSVpvn(key, klen); SvUTF8_on(keysv); } if (PL_tainting) PL_tainted = SvTAINTED(keysv); keysv = sv_2mortal(newSVsv(keysv)); mg_copy((SV*)hv, val, (char*)keysv, HEf_SVKEY); } else { mg_copy((SV*)hv, val, key, klen); } TAINT_IF(save_taint); if (!xhv->xhv_array /* !HvARRAY(hv) */ && !needs_store) { if (flags & HVhek_FREEKEY) Safefree(key); return Nullhe; } #ifdef ENV_IS_CASELESS else if (mg_find((SV*)hv, PERL_MAGIC_env)) { /* XXX This code isn't UTF8 clean. */ const char *keysave = key; /* Will need to free this, so set FREEKEY flag. */ key = savepvn(key,klen); key = (const char*)strupr((char*)key); is_utf8 = 0; hash = 0; keysv = 0; if (flags & HVhek_FREEKEY) { Safefree(keysave); } flags |= HVhek_FREEKEY; } #endif } } /* ISSTORE */ } /* SvMAGICAL */ if (!xhv->xhv_array /* !HvARRAY(hv) */) { if ((action & (HV_FETCH_LVALUE | HV_FETCH_ISSTORE)) #ifdef DYNAMIC_ENV_FETCH /* if it's an %ENV lookup, we may get it on the fly */ || (SvRMAGICAL((SV*)hv) && mg_find((SV*)hv, PERL_MAGIC_env)) #endif ) Newz(503, xhv->xhv_array /* HvARRAY(hv) */, PERL_HV_ARRAY_ALLOC_BYTES(xhv->xhv_max+1 /* HvMAX(hv)+1 */), char); #ifdef DYNAMIC_ENV_FETCH else if (action & HV_FETCH_ISEXISTS) { /* for an %ENV exists, if we do an insert it's by a recursive store call, so avoid creating HvARRAY(hv) right now. */ } #endif else { /* XXX remove at some point? */ if (flags & HVhek_FREEKEY) Safefree(key); return 0; } } if (is_utf8) { const char *keysave = key; key = (char*)bytes_from_utf8((U8*)key, &klen, &is_utf8); if (is_utf8) flags |= HVhek_UTF8; else flags &= ~HVhek_UTF8; if (key != keysave) { if (flags & HVhek_FREEKEY) Safefree(keysave); flags |= HVhek_WASUTF8 | HVhek_FREEKEY; } } if (HvREHASH(hv)) { PERL_HASH_INTERNAL(hash, key, klen); /* We don't have a pointer to the hv, so we have to replicate the flag into every HEK, so that hv_iterkeysv can see it. */ /* And yes, you do need this even though you are not "storing" because you can flip the flags below if doing an lval lookup. (And that was put in to give the semantics Andreas was expecting.) */ flags |= HVhek_REHASH; } else if (!hash) { /* Not enough shared hash key scalars around to make this worthwhile (about 4% slowdown in perlbench with this in) if (keysv && (SvIsCOW_shared_hash(keysv))) { hash = SvUVX(keysv); } else */ { PERL_HASH(hash, key, klen); } } masked_flags = (flags & HVhek_MASK); n_links = 0; #ifdef DYNAMIC_ENV_FETCH if (!xhv->xhv_array /* !HvARRAY(hv) */) entry = Null(HE*); else #endif { /* entry = (HvARRAY(hv))[hash & (I32) HvMAX(hv)]; */ entry = ((HE**)xhv->xhv_array)[hash & (I32) xhv->xhv_max]; } for (; entry; ++n_links, entry = HeNEXT(entry)) { if (HeHASH(entry) != hash) /* strings can't be equal */ continue; if (HeKLEN(entry) != (I32)klen) continue; if (HeKEY(entry) != key && memNE(HeKEY(entry),key,klen)) /* is this it? */ continue; if ((HeKFLAGS(entry) ^ masked_flags) & HVhek_UTF8) continue; if (action & (HV_FETCH_LVALUE|HV_FETCH_ISSTORE)) { if (HeKFLAGS(entry) != masked_flags) { /* We match if HVhek_UTF8 bit in our flags and hash key's match. But if entry was set previously with HVhek_WASUTF8 and key now doesn't (or vice versa) then we should change the key's flag, as this is assignment. */ if (HvSHAREKEYS(hv)) { /* Need to swap the key we have for a key with the flags we need. As keys are shared we can't just write to the flag, so we share the new one, unshare the old one. */ HEK *new_hek = share_hek_flags(key, klen, hash, masked_flags); unshare_hek (HeKEY_hek(entry)); HeKEY_hek(entry) = new_hek; } else HeKFLAGS(entry) = masked_flags; if (masked_flags & HVhek_ENABLEHVKFLAGS) HvHASKFLAGS_on(hv); } if (HeVAL(entry) == &PL_sv_placeholder) { /* yes, can store into placeholder slot */ if (action & HV_FETCH_LVALUE) { if (SvMAGICAL(hv)) { /* This preserves behaviour with the old hv_fetch implementation which at this point would bail out with a break; (at "if we find a placeholder, we pretend we haven't found anything") That break mean that if a placeholder were found, it caused a call into hv_store, which in turn would check magic, and if there is no magic end up pretty much back at this point (in hv_store's code). */ break; } /* LVAL fetch which actaully needs a store. */ val = NEWSV(61,0); xhv->xhv_placeholders--; } else { /* store */ if (val != &PL_sv_placeholder) xhv->xhv_placeholders--; } HeVAL(entry) = val; } else if (action & HV_FETCH_ISSTORE) { SvREFCNT_dec(HeVAL(entry)); HeVAL(entry) = val; } } else if (HeVAL(entry) == &PL_sv_placeholder) { /* if we find a placeholder, we pretend we haven't found anything */ break; } if (flags & HVhek_FREEKEY) Safefree(key); return entry; } #ifdef DYNAMIC_ENV_FETCH /* %ENV lookup? If so, try to fetch the value now */ if (!(action & HV_FETCH_ISSTORE) && SvRMAGICAL((SV*)hv) && mg_find((SV*)hv, PERL_MAGIC_env)) { unsigned long len; char *env = PerlEnv_ENVgetenv_len(key,&len); if (env) { sv = newSVpvn(env,len); SvTAINTED_on(sv); return hv_fetch_common(hv,keysv,key,klen,flags,HV_FETCH_ISSTORE,sv, hash); } } #endif if (!entry && SvREADONLY(hv) && !(action & HV_FETCH_ISEXISTS)) { S_hv_notallowed(aTHX_ flags, key, klen, "access disallowed key '%"SVf"' in" ); } if (!(action & (HV_FETCH_LVALUE|HV_FETCH_ISSTORE))) { /* Not doing some form of store, so return failure. */ if (flags & HVhek_FREEKEY) Safefree(key); return 0; } if (action & HV_FETCH_LVALUE) { val = NEWSV(61,0); if (SvMAGICAL(hv)) { /* At this point the old hv_fetch code would call to hv_store, which in turn might do some tied magic. So we need to make that magic check happen. */ /* gonna assign to this, so it better be there */ return hv_fetch_common(hv, keysv, key, klen, flags, HV_FETCH_ISSTORE, val, hash); /* XXX Surely that could leak if the fetch-was-store fails? Just like the hv_fetch. */ } } /* Welcome to hv_store... */ if (!xhv->xhv_array) { /* Not sure if we can get here. I think the only case of oentry being NULL is for %ENV with dynamic env fetch. But that should disappear with magic in the previous code. */ Newz(503, xhv->xhv_array /* HvARRAY(hv) */, PERL_HV_ARRAY_ALLOC_BYTES(xhv->xhv_max+1 /* HvMAX(hv)+1 */), char); } oentry = &((HE**)xhv->xhv_array)[hash & (I32) xhv->xhv_max]; entry = new_HE(); /* share_hek_flags will do the free for us. This might be considered bad API design. */ if (HvSHAREKEYS(hv)) HeKEY_hek(entry) = share_hek_flags(key, klen, hash, flags); else /* gotta do the real thing */ HeKEY_hek(entry) = save_hek_flags(key, klen, hash, flags); HeVAL(entry) = val; HeNEXT(entry) = *oentry; *oentry = entry; if (val == &PL_sv_placeholder) xhv->xhv_placeholders++; if (masked_flags & HVhek_ENABLEHVKFLAGS) HvHASKFLAGS_on(hv); xhv->xhv_keys++; /* HvKEYS(hv)++ */ if (!n_links) { /* initial entry? */ xhv->xhv_fill++; /* HvFILL(hv)++ */ } else if ((xhv->xhv_keys > (IV)xhv->xhv_max) || ((n_links > HV_MAX_LENGTH_BEFORE_SPLIT) && !HvREHASH(hv))) { /* Use only the old HvKEYS(hv) > HvMAX(hv) condition to limit bucket splits on a rehashed hash, as we're not going to split it again, and if someone is lucky (evil) enough to get all the keys in one list they could exhaust our memory as we repeatedly double the number of buckets on every entry. Linear search feels a less worse thing to do. */ hsplit(hv); } return entry; } STATIC void S_hv_magic_check(pTHX_ HV *hv, bool *needs_copy, bool *needs_store) { MAGIC *mg = SvMAGIC(hv); *needs_copy = FALSE; *needs_store = TRUE; while (mg) { if (isUPPER(mg->mg_type)) { *needs_copy = TRUE; switch (mg->mg_type) { case PERL_MAGIC_tied: case PERL_MAGIC_sig: *needs_store = FALSE; } } mg = mg->mg_moremagic; } } /* =for apidoc hv_scalar Evaluates the hash in scalar context and returns the result. Handles magic when the hash is tied. =cut */ SV * Perl_hv_scalar(pTHX_ HV *hv) { MAGIC *mg; SV *sv; if ((SvRMAGICAL(hv) && (mg = mg_find((SV*)hv, PERL_MAGIC_tied)))) { sv = magic_scalarpack(hv, mg); return sv; } sv = sv_newmortal(); if (HvFILL((HV*)hv)) Perl_sv_setpvf(aTHX_ sv, "%ld/%ld", (long)HvFILL(hv), (long)HvMAX(hv) + 1); else sv_setiv(sv, 0); return sv; } /* =for apidoc hv_delete Deletes a key/value pair in the hash. The value SV is removed from the hash and returned to the caller. The C is the length of the key. The C value will normally be zero; if set to G_DISCARD then NULL will be returned. =cut */ SV * Perl_hv_delete(pTHX_ HV *hv, const char *key, I32 klen_i32, I32 flags) { STRLEN klen; int k_flags = 0; if (klen_i32 < 0) { klen = -klen_i32; k_flags |= HVhek_UTF8; } else { klen = klen_i32; } return hv_delete_common(hv, NULL, key, klen, k_flags, flags, 0); } /* =for apidoc hv_delete_ent Deletes a key/value pair in the hash. The value SV is removed from the hash and returned to the caller. The C value will normally be zero; if set to G_DISCARD then NULL will be returned. C can be a valid precomputed hash value, or 0 to ask for it to be computed. =cut */ SV * Perl_hv_delete_ent(pTHX_ HV *hv, SV *keysv, I32 flags, U32 hash) { return hv_delete_common(hv, keysv, NULL, 0, 0, flags, hash); } STATIC SV * S_hv_delete_common(pTHX_ HV *hv, SV *keysv, const char *key, STRLEN klen, int k_flags, I32 d_flags, U32 hash) { register XPVHV* xhv; register I32 i; register HE *entry; register HE **oentry; SV *sv; bool is_utf8; int masked_flags; if (!hv) return Nullsv; if (keysv) { if (k_flags & HVhek_FREEKEY) Safefree(key); key = SvPV(keysv, klen); k_flags = 0; is_utf8 = (SvUTF8(keysv) != 0); } else { is_utf8 = ((k_flags & HVhek_UTF8) ? TRUE : FALSE); } if (SvRMAGICAL(hv)) { bool needs_copy; bool needs_store; hv_magic_check (hv, &needs_copy, &needs_store); if (needs_copy) { entry = hv_fetch_common(hv, keysv, key, klen, k_flags & ~HVhek_FREEKEY, HV_FETCH_LVALUE, Nullsv, hash); sv = entry ? HeVAL(entry) : NULL; if (sv) { if (SvMAGICAL(sv)) { mg_clear(sv); } if (!needs_store) { if (mg_find(sv, PERL_MAGIC_tiedelem)) { /* No longer an element */ sv_unmagic(sv, PERL_MAGIC_tiedelem); return sv; } return Nullsv; /* element cannot be deleted */ } #ifdef ENV_IS_CASELESS else if (mg_find((SV*)hv, PERL_MAGIC_env)) { /* XXX This code isn't UTF8 clean. */ keysv = sv_2mortal(newSVpvn(key,klen)); if (k_flags & HVhek_FREEKEY) { Safefree(key); } key = strupr(SvPVX(keysv)); is_utf8 = 0; k_flags = 0; hash = 0; } #endif } } } xhv = (XPVHV*)SvANY(hv); if (!xhv->xhv_array /* !HvARRAY(hv) */) return Nullsv; if (is_utf8) { const char *keysave = key; key = (char*)bytes_from_utf8((U8*)key, &klen, &is_utf8); if (is_utf8) k_flags |= HVhek_UTF8; else k_flags &= ~HVhek_UTF8; if (key != keysave) { if (k_flags & HVhek_FREEKEY) { /* This shouldn't happen if our caller does what we expect, but strictly the API allows it. */ Safefree(keysave); } k_flags |= HVhek_WASUTF8 | HVhek_FREEKEY; } HvHASKFLAGS_on((SV*)hv); } if (HvREHASH(hv)) { PERL_HASH_INTERNAL(hash, key, klen); } else if (!hash) { /* Not enough shared hash key scalars around to make this worthwhile (about 4% slowdown in perlbench with this in) if (keysv && (SvIsCOW_shared_hash(keysv))) { hash = SvUVX(keysv); } else */ { PERL_HASH(hash, key, klen); } } masked_flags = (k_flags & HVhek_MASK); /* oentry = &(HvARRAY(hv))[hash & (I32) HvMAX(hv)]; */ oentry = &((HE**)xhv->xhv_array)[hash & (I32) xhv->xhv_max]; entry = *oentry; i = 1; for (; entry; i=0, oentry = &HeNEXT(entry), entry = *oentry) { if (HeHASH(entry) != hash) /* strings can't be equal */ continue; if (HeKLEN(entry) != (I32)klen) continue; if (HeKEY(entry) != key && memNE(HeKEY(entry),key,klen)) /* is this it? */ continue; if ((HeKFLAGS(entry) ^ masked_flags) & HVhek_UTF8) continue; /* if placeholder is here, it's already been deleted.... */ if (HeVAL(entry) == &PL_sv_placeholder) { if (k_flags & HVhek_FREEKEY) Safefree(key); return Nullsv; } else if (SvREADONLY(hv) && HeVAL(entry) && SvREADONLY(HeVAL(entry))) { S_hv_notallowed(aTHX_ k_flags, key, klen, "delete readonly key '%"SVf"' from" ); } if (k_flags & HVhek_FREEKEY) Safefree(key); if (d_flags & G_DISCARD) sv = Nullsv; else { sv = sv_2mortal(HeVAL(entry)); HeVAL(entry) = &PL_sv_placeholder; } /* * If a restricted hash, rather than really deleting the entry, put * a placeholder there. This marks the key as being "approved", so * we can still access via not-really-existing key without raising * an error. */ if (SvREADONLY(hv)) { SvREFCNT_dec(HeVAL(entry)); HeVAL(entry) = &PL_sv_placeholder; /* We'll be saving this slot, so the number of allocated keys * doesn't go down, but the number placeholders goes up */ xhv->xhv_placeholders++; /* HvPLACEHOLDERS(hv)++ */ } else { *oentry = HeNEXT(entry); if (i && !*oentry) xhv->xhv_fill--; /* HvFILL(hv)-- */ if (entry == xhv->xhv_eiter /* HvEITER(hv) */) HvLAZYDEL_on(hv); else hv_free_ent(hv, entry); xhv->xhv_keys--; /* HvKEYS(hv)-- */ if (xhv->xhv_keys == 0) HvHASKFLAGS_off(hv); } return sv; } if (SvREADONLY(hv)) { S_hv_notallowed(aTHX_ k_flags, key, klen, "delete disallowed key '%"SVf"' from" ); } if (k_flags & HVhek_FREEKEY) Safefree(key); return Nullsv; } STATIC void S_hsplit(pTHX_ HV *hv) { register XPVHV* xhv = (XPVHV*)SvANY(hv); I32 oldsize = (I32) xhv->xhv_max+1; /* HvMAX(hv)+1 (sick) */ register I32 newsize = oldsize * 2; register I32 i; register char *a = xhv->xhv_array; /* HvARRAY(hv) */ register HE **aep; register HE **bep; register HE *entry; register HE **oentry; int longest_chain = 0; int was_shared; /*PerlIO_printf(PerlIO_stderr(), "hsplit called for %p which had %d\n", hv, (int) oldsize);*/ if (HvPLACEHOLDERS(hv) && !SvREADONLY(hv)) { /* Can make this clear any placeholders first for non-restricted hashes, even though Storable rebuilds restricted hashes by putting in all the placeholders (first) before turning on the readonly flag, because Storable always pre-splits the hash. */ hv_clear_placeholders(hv); } PL_nomemok = TRUE; #if defined(STRANGE_MALLOC) || defined(MYMALLOC) Renew(a, PERL_HV_ARRAY_ALLOC_BYTES(newsize), char); if (!a) { PL_nomemok = FALSE; return; } #else New(2, a, PERL_HV_ARRAY_ALLOC_BYTES(newsize), char); if (!a) { PL_nomemok = FALSE; return; } Copy(xhv->xhv_array /* HvARRAY(hv) */, a, oldsize * sizeof(HE*), char); if (oldsize >= 64) { offer_nice_chunk(xhv->xhv_array /* HvARRAY(hv) */, PERL_HV_ARRAY_ALLOC_BYTES(oldsize)); } else Safefree(xhv->xhv_array /* HvARRAY(hv) */); #endif PL_nomemok = FALSE; Zero(&a[oldsize * sizeof(HE*)], (newsize-oldsize) * sizeof(HE*), char); /* zero 2nd half*/ xhv->xhv_max = --newsize; /* HvMAX(hv) = --newsize */ xhv->xhv_array = a; /* HvARRAY(hv) = a */ aep = (HE**)a; for (i=0; ixhv_fill++; /* HvFILL(hv)++ */ *bep = entry; right_length++; continue; } else { oentry = &HeNEXT(entry); left_length++; } } if (!*aep) /* everything moved */ xhv->xhv_fill--; /* HvFILL(hv)-- */ /* I think we don't actually need to keep track of the longest length, merely flag if anything is too long. But for the moment while developing this code I'll track it. */ if (left_length > longest_chain) longest_chain = left_length; if (right_length > longest_chain) longest_chain = right_length; } /* Pick your policy for "hashing isn't working" here: */ if (longest_chain <= HV_MAX_LENGTH_BEFORE_SPLIT /* split worked? */ || HvREHASH(hv)) { return; } if (hv == PL_strtab) { /* Urg. Someone is doing something nasty to the string table. Can't win. */ return; } /* Awooga. Awooga. Pathological data. */ /*PerlIO_printf(PerlIO_stderr(), "%p %d of %d with %d/%d buckets\n", hv, longest_chain, HvTOTALKEYS(hv), HvFILL(hv), 1+HvMAX(hv));*/ ++newsize; Newz(2, a, PERL_HV_ARRAY_ALLOC_BYTES(newsize), char); was_shared = HvSHAREKEYS(hv); xhv->xhv_fill = 0; HvSHAREKEYS_off(hv); HvREHASH_on(hv); aep = (HE **) xhv->xhv_array; for (i=0; ixhv_max); if (!*bep) xhv->xhv_fill++; /* HvFILL(hv)++ */ HeNEXT(entry) = *bep; *bep = entry; entry = next; } } Safefree (xhv->xhv_array); xhv->xhv_array = a; /* HvARRAY(hv) = a */ } void Perl_hv_ksplit(pTHX_ HV *hv, IV newmax) { register XPVHV* xhv = (XPVHV*)SvANY(hv); I32 oldsize = (I32) xhv->xhv_max+1; /* HvMAX(hv)+1 (sick) */ register I32 newsize; register I32 i; register I32 j; register char *a; register HE **aep; register HE *entry; register HE **oentry; newsize = (I32) newmax; /* possible truncation here */ if (newsize != newmax || newmax <= oldsize) return; while ((newsize & (1 + ~newsize)) != newsize) { newsize &= ~(newsize & (1 + ~newsize)); /* get proper power of 2 */ } if (newsize < newmax) newsize *= 2; if (newsize < newmax) return; /* overflow detection */ a = xhv->xhv_array; /* HvARRAY(hv) */ if (a) { PL_nomemok = TRUE; #if defined(STRANGE_MALLOC) || defined(MYMALLOC) Renew(a, PERL_HV_ARRAY_ALLOC_BYTES(newsize), char); if (!a) { PL_nomemok = FALSE; return; } #else New(2, a, PERL_HV_ARRAY_ALLOC_BYTES(newsize), char); if (!a) { PL_nomemok = FALSE; return; } Copy(xhv->xhv_array /* HvARRAY(hv) */, a, oldsize * sizeof(HE*), char); if (oldsize >= 64) { offer_nice_chunk(xhv->xhv_array /* HvARRAY(hv) */, PERL_HV_ARRAY_ALLOC_BYTES(oldsize)); } else Safefree(xhv->xhv_array /* HvARRAY(hv) */); #endif PL_nomemok = FALSE; Zero(&a[oldsize * sizeof(HE*)], (newsize-oldsize) * sizeof(HE*), char); /* zero 2nd half*/ } else { Newz(0, a, PERL_HV_ARRAY_ALLOC_BYTES(newsize), char); } xhv->xhv_max = --newsize; /* HvMAX(hv) = --newsize */ xhv->xhv_array = a; /* HvARRAY(hv) = a */ if (!xhv->xhv_fill /* !HvFILL(hv) */) /* skip rest if no entries */ return; aep = (HE**)a; for (i=0; ixhv_fill++; /* HvFILL(hv)++ */ aep[j] = entry; continue; } else oentry = &HeNEXT(entry); } if (!*aep) /* everything moved */ xhv->xhv_fill--; /* HvFILL(hv)-- */ } } /* =for apidoc newHV Creates a new HV. The reference count is set to 1. =cut */ HV * Perl_newHV(pTHX) { register HV *hv; register XPVHV* xhv; hv = (HV*)NEWSV(502,0); sv_upgrade((SV *)hv, SVt_PVHV); xhv = (XPVHV*)SvANY(hv); SvPOK_off(hv); SvNOK_off(hv); #ifndef NODEFAULT_SHAREKEYS HvSHAREKEYS_on(hv); /* key-sharing on by default */ #endif xhv->xhv_max = 7; /* HvMAX(hv) = 7 (start with 8 buckets) */ xhv->xhv_fill = 0; /* HvFILL(hv) = 0 */ xhv->xhv_pmroot = 0; /* HvPMROOT(hv) = 0 */ (void)hv_iterinit(hv); /* so each() will start off right */ return hv; } HV * Perl_newHVhv(pTHX_ HV *ohv) { HV *hv = newHV(); STRLEN hv_max, hv_fill; if (!ohv || (hv_fill = HvFILL(ohv)) == 0) return hv; hv_max = HvMAX(ohv); if (!SvMAGICAL((SV *)ohv)) { /* It's an ordinary hash, so copy it fast. AMS 20010804 */ STRLEN i; bool shared = !!HvSHAREKEYS(ohv); HE **ents, **oents = (HE **)HvARRAY(ohv); char *a; New(0, a, PERL_HV_ARRAY_ALLOC_BYTES(hv_max+1), char); ents = (HE**)a; /* In each bucket... */ for (i = 0; i <= hv_max; i++) { HE *prev = NULL, *ent = NULL, *oent = oents[i]; if (!oent) { ents[i] = NULL; continue; } /* Copy the linked list of entries. */ for (oent = oents[i]; oent; oent = HeNEXT(oent)) { U32 hash = HeHASH(oent); char *key = HeKEY(oent); STRLEN len = HeKLEN(oent); int flags = HeKFLAGS(oent); ent = new_HE(); HeVAL(ent) = newSVsv(HeVAL(oent)); HeKEY_hek(ent) = shared ? share_hek_flags(key, len, hash, flags) : save_hek_flags(key, len, hash, flags); if (prev) HeNEXT(prev) = ent; else ents[i] = ent; prev = ent; HeNEXT(ent) = NULL; } } HvMAX(hv) = hv_max; HvFILL(hv) = hv_fill; HvTOTALKEYS(hv) = HvTOTALKEYS(ohv); HvARRAY(hv) = ents; } else { /* Iterate over ohv, copying keys and values one at a time. */ HE *entry; I32 riter = HvRITER(ohv); HE *eiter = HvEITER(ohv); /* Can we use fewer buckets? (hv_max is always 2^n-1) */ while (hv_max && hv_max + 1 >= hv_fill * 2) hv_max = hv_max / 2; HvMAX(hv) = hv_max; hv_iterinit(ohv); while ((entry = hv_iternext_flags(ohv, 0))) { hv_store_flags(hv, HeKEY(entry), HeKLEN(entry), newSVsv(HeVAL(entry)), HeHASH(entry), HeKFLAGS(entry)); } HvRITER(ohv) = riter; HvEITER(ohv) = eiter; } return hv; } void Perl_hv_free_ent(pTHX_ HV *hv, register HE *entry) { SV *val; if (!entry) return; val = HeVAL(entry); if (val && isGV(val) && GvCVu(val) && HvNAME(hv)) PL_sub_generation++; /* may be deletion of method from stash */ SvREFCNT_dec(val); if (HeKLEN(entry) == HEf_SVKEY) { SvREFCNT_dec(HeKEY_sv(entry)); Safefree(HeKEY_hek(entry)); } else if (HvSHAREKEYS(hv)) unshare_hek(HeKEY_hek(entry)); else Safefree(HeKEY_hek(entry)); del_HE(entry); } void Perl_hv_delayfree_ent(pTHX_ HV *hv, register HE *entry) { if (!entry) return; if (isGV(HeVAL(entry)) && GvCVu(HeVAL(entry)) && HvNAME(hv)) PL_sub_generation++; /* may be deletion of method from stash */ sv_2mortal(HeVAL(entry)); /* free between statements */ if (HeKLEN(entry) == HEf_SVKEY) { sv_2mortal(HeKEY_sv(entry)); Safefree(HeKEY_hek(entry)); } else if (HvSHAREKEYS(hv)) unshare_hek(HeKEY_hek(entry)); else Safefree(HeKEY_hek(entry)); del_HE(entry); } /* =for apidoc hv_clear Clears a hash, making it empty. =cut */ void Perl_hv_clear(pTHX_ HV *hv) { register XPVHV* xhv; if (!hv) return; xhv = (XPVHV*)SvANY(hv); if (SvREADONLY(hv) && xhv->xhv_array != NULL) { /* restricted hash: convert all keys to placeholders */ I32 i; HE* entry; for (i = 0; i <= (I32) xhv->xhv_max; i++) { entry = ((HE**)xhv->xhv_array)[i]; for (; entry; entry = HeNEXT(entry)) { /* not already placeholder */ if (HeVAL(entry) != &PL_sv_placeholder) { if (HeVAL(entry) && SvREADONLY(HeVAL(entry))) { SV* keysv = hv_iterkeysv(entry); Perl_croak(aTHX_ "Attempt to delete readonly key '%"SVf"' from a restricted hash", keysv); } SvREFCNT_dec(HeVAL(entry)); HeVAL(entry) = &PL_sv_placeholder; xhv->xhv_placeholders++; /* HvPLACEHOLDERS(hv)++ */ } } } goto reset; } hfreeentries(hv); xhv->xhv_placeholders = 0; /* HvPLACEHOLDERS(hv) = 0 */ if (xhv->xhv_array /* HvARRAY(hv) */) (void)memzero(xhv->xhv_array /* HvARRAY(hv) */, (xhv->xhv_max+1 /* HvMAX(hv)+1 */) * sizeof(HE*)); if (SvRMAGICAL(hv)) mg_clear((SV*)hv); HvHASKFLAGS_off(hv); HvREHASH_off(hv); reset: HvEITER(hv) = NULL; } /* =for apidoc hv_clear_placeholders Clears any placeholders from a hash. If a restricted hash has any of its keys marked as readonly and the key is subsequently deleted, the key is not actually deleted but is marked by assigning it a value of &PL_sv_placeholder. This tags it so it will be ignored by future operations such as iterating over the hash, but will still allow the hash to have a value reassigned to the key at some future point. This function clears any such placeholder keys from the hash. See Hash::Util::lock_keys() for an example of its use. =cut */ void Perl_hv_clear_placeholders(pTHX_ HV *hv) { I32 items = (I32)HvPLACEHOLDERS(hv); I32 i = HvMAX(hv); if (items == 0) return; do { /* Loop down the linked list heads */ int first = 1; HE **oentry = &(HvARRAY(hv))[i]; HE *entry = *oentry; if (!entry) continue; for (; entry; entry = *oentry) { if (HeVAL(entry) == &PL_sv_placeholder) { *oentry = HeNEXT(entry); if (first && !*oentry) HvFILL(hv)--; /* This linked list is now empty. */ if (HvEITER(hv)) HvLAZYDEL_on(hv); else hv_free_ent(hv, entry); if (--items == 0) { /* Finished. */ HvTOTALKEYS(hv) -= HvPLACEHOLDERS(hv); if (HvKEYS(hv) == 0) HvHASKFLAGS_off(hv); HvPLACEHOLDERS(hv) = 0; return; } } else { oentry = &HeNEXT(entry); first = 0; } } } while (--i >= 0); /* You can't get here, hence assertion should always fail. */ assert (items == 0); assert (0); } STATIC void S_hfreeentries(pTHX_ HV *hv) { register HE **array; register HE *entry; register HE *oentry = Null(HE*); I32 riter; I32 max; if (!hv) return; if (!HvARRAY(hv)) return; riter = 0; max = HvMAX(hv); array = HvARRAY(hv); /* make everyone else think the array is empty, so that the destructors * called for freed entries can't recusively mess with us */ HvARRAY(hv) = Null(HE**); HvFILL(hv) = 0; ((XPVHV*) SvANY(hv))->xhv_keys = 0; entry = array[0]; for (;;) { if (entry) { oentry = entry; entry = HeNEXT(entry); hv_free_ent(hv, oentry); } if (!entry) { if (++riter > max) break; entry = array[riter]; } } HvARRAY(hv) = array; (void)hv_iterinit(hv); } /* =for apidoc hv_undef Undefines the hash. =cut */ void Perl_hv_undef(pTHX_ HV *hv) { register XPVHV* xhv; if (!hv) return; xhv = (XPVHV*)SvANY(hv); hfreeentries(hv); Safefree(xhv->xhv_array /* HvARRAY(hv) */); if (HvNAME(hv)) { if(PL_stashcache) hv_delete(PL_stashcache, HvNAME(hv), strlen(HvNAME(hv)), G_DISCARD); Safefree(HvNAME(hv)); HvNAME(hv) = 0; } xhv->xhv_max = 7; /* HvMAX(hv) = 7 (it's a normal hash) */ xhv->xhv_array = 0; /* HvARRAY(hv) = 0 */ xhv->xhv_placeholders = 0; /* HvPLACEHOLDERS(hv) = 0 */ if (SvRMAGICAL(hv)) mg_clear((SV*)hv); } /* =for apidoc hv_iterinit Prepares a starting point to traverse a hash table. Returns the number of keys in the hash (i.e. the same as C). The return value is currently only meaningful for hashes without tie magic. NOTE: Before version 5.004_65, C used to return the number of hash buckets that happen to be in use. If you still need that esoteric value, you can get it through the macro C. =cut */ I32 Perl_hv_iterinit(pTHX_ HV *hv) { register XPVHV* xhv; HE *entry; if (!hv) Perl_croak(aTHX_ "Bad hash"); xhv = (XPVHV*)SvANY(hv); entry = xhv->xhv_eiter; /* HvEITER(hv) */ if (entry && HvLAZYDEL(hv)) { /* was deleted earlier? */ HvLAZYDEL_off(hv); hv_free_ent(hv, entry); } xhv->xhv_riter = -1; /* HvRITER(hv) = -1 */ xhv->xhv_eiter = Null(HE*); /* HvEITER(hv) = Null(HE*) */ /* used to be xhv->xhv_fill before 5.004_65 */ return XHvTOTALKEYS(xhv); } /* =for apidoc hv_iternext Returns entries from a hash iterator. See C. You may call C or C on the hash entry that the iterator currently points to, without losing your place or invalidating your iterator. Note that in this case the current entry is deleted from the hash with your iterator holding the last reference to it. Your iterator is flagged to free the entry on the next call to C, so you must not discard your iterator immediately else the entry will leak - call C to trigger the resource deallocation. =cut */ HE * Perl_hv_iternext(pTHX_ HV *hv) { return hv_iternext_flags(hv, 0); } /* =for apidoc hv_iternext_flags Returns entries from a hash iterator. See C and C. The C value will normally be zero; if HV_ITERNEXT_WANTPLACEHOLDERS is set the placeholders keys (for restricted hashes) will be returned in addition to normal keys. By default placeholders are automatically skipped over. Currently a placeholder is implemented with a value that is C<&Perl_sv_placeholder>. Note that the implementation of placeholders and restricted hashes may change, and the implementation currently is insufficiently abstracted for any change to be tidy. =cut */ HE * Perl_hv_iternext_flags(pTHX_ HV *hv, I32 flags) { register XPVHV* xhv; register HE *entry; HE *oldentry; MAGIC* mg; if (!hv) Perl_croak(aTHX_ "Bad hash"); xhv = (XPVHV*)SvANY(hv); oldentry = entry = xhv->xhv_eiter; /* HvEITER(hv) */ if ((mg = SvTIED_mg((SV*)hv, PERL_MAGIC_tied))) { SV *key = sv_newmortal(); if (entry) { sv_setsv(key, HeSVKEY_force(entry)); SvREFCNT_dec(HeSVKEY(entry)); /* get rid of previous key */ } else { char *k; HEK *hek; /* one HE per MAGICAL hash */ xhv->xhv_eiter = entry = new_HE(); /* HvEITER(hv) = new_HE() */ Zero(entry, 1, HE); Newz(54, k, HEK_BASESIZE + sizeof(SV*), char); hek = (HEK*)k; HeKEY_hek(entry) = hek; HeKLEN(entry) = HEf_SVKEY; } magic_nextpack((SV*) hv,mg,key); if (SvOK(key)) { /* force key to stay around until next time */ HeSVKEY_set(entry, SvREFCNT_inc(key)); return entry; /* beware, hent_val is not set */ } if (HeVAL(entry)) SvREFCNT_dec(HeVAL(entry)); Safefree(HeKEY_hek(entry)); del_HE(entry); xhv->xhv_eiter = Null(HE*); /* HvEITER(hv) = Null(HE*) */ return Null(HE*); } #ifdef DYNAMIC_ENV_FETCH /* set up %ENV for iteration */ if (!entry && SvRMAGICAL((SV*)hv) && mg_find((SV*)hv, PERL_MAGIC_env)) prime_env_iter(); #endif if (!xhv->xhv_array /* !HvARRAY(hv) */) Newz(506, xhv->xhv_array /* HvARRAY(hv) */, PERL_HV_ARRAY_ALLOC_BYTES(xhv->xhv_max+1 /* HvMAX(hv)+1 */), char); /* At start of hash, entry is NULL. */ if (entry) { entry = HeNEXT(entry); if (!(flags & HV_ITERNEXT_WANTPLACEHOLDERS)) { /* * Skip past any placeholders -- don't want to include them in * any iteration. */ while (entry && HeVAL(entry) == &PL_sv_placeholder) { entry = HeNEXT(entry); } } } while (!entry) { /* OK. Come to the end of the current list. Grab the next one. */ xhv->xhv_riter++; /* HvRITER(hv)++ */ if (xhv->xhv_riter > (I32)xhv->xhv_max /* HvRITER(hv) > HvMAX(hv) */) { /* There is no next one. End of the hash. */ xhv->xhv_riter = -1; /* HvRITER(hv) = -1 */ break; } /* entry = (HvARRAY(hv))[HvRITER(hv)]; */ entry = ((HE**)xhv->xhv_array)[xhv->xhv_riter]; if (!(flags & HV_ITERNEXT_WANTPLACEHOLDERS)) { /* If we have an entry, but it's a placeholder, don't count it. Try the next. */ while (entry && HeVAL(entry) == &PL_sv_placeholder) entry = HeNEXT(entry); } /* Will loop again if this linked list starts NULL (for HV_ITERNEXT_WANTPLACEHOLDERS) or if we run through it and find only placeholders. */ } if (oldentry && HvLAZYDEL(hv)) { /* was deleted earlier? */ HvLAZYDEL_off(hv); hv_free_ent(hv, oldentry); } /*if (HvREHASH(hv) && entry && !HeKREHASH(entry)) PerlIO_printf(PerlIO_stderr(), "Awooga %p %p\n", hv, entry);*/ xhv->xhv_eiter = entry; /* HvEITER(hv) = entry */ return entry; } /* =for apidoc hv_iterkey Returns the key from the current position of the hash iterator. See C. =cut */ char * Perl_hv_iterkey(pTHX_ register HE *entry, I32 *retlen) { if (HeKLEN(entry) == HEf_SVKEY) { STRLEN len; char *p = SvPV(HeKEY_sv(entry), len); *retlen = len; return p; } else { *retlen = HeKLEN(entry); return HeKEY(entry); } } /* unlike hv_iterval(), this always returns a mortal copy of the key */ /* =for apidoc hv_iterkeysv Returns the key as an C from the current position of the hash iterator. The return value will always be a mortal copy of the key. Also see C. =cut */ SV * Perl_hv_iterkeysv(pTHX_ register HE *entry) { if (HeKLEN(entry) != HEf_SVKEY) { HEK *hek = HeKEY_hek(entry); int flags = HEK_FLAGS(hek); SV *sv; if (flags & HVhek_WASUTF8) { /* Trouble :-) Andreas would like keys he put in as utf8 to come back as utf8 */ STRLEN utf8_len = HEK_LEN(hek); U8 *as_utf8 = bytes_to_utf8 ((U8*)HEK_KEY(hek), &utf8_len); sv = newSVpvn ((char*)as_utf8, utf8_len); SvUTF8_on (sv); Safefree (as_utf8); /* bytes_to_utf8() allocates a new string */ } else if (flags & HVhek_REHASH) { /* We don't have a pointer to the hv, so we have to replicate the flag into every HEK. This hv is using custom a hasing algorithm. Hence we can't return a shared string scalar, as that would contain the (wrong) hash value, and might get passed into an hv routine with a regular hash */ sv = newSVpvn (HEK_KEY(hek), HEK_LEN(hek)); if (HEK_UTF8(hek)) SvUTF8_on (sv); } else { sv = newSVpvn_share(HEK_KEY(hek), (HEK_UTF8(hek) ? -HEK_LEN(hek) : HEK_LEN(hek)), HEK_HASH(hek)); } return sv_2mortal(sv); } return sv_mortalcopy(HeKEY_sv(entry)); } /* =for apidoc hv_iterval Returns the value from the current position of the hash iterator. See C. =cut */ SV * Perl_hv_iterval(pTHX_ HV *hv, register HE *entry) { if (SvRMAGICAL(hv)) { if (mg_find((SV*)hv, PERL_MAGIC_tied)) { SV* sv = sv_newmortal(); if (HeKLEN(entry) == HEf_SVKEY) mg_copy((SV*)hv, sv, (char*)HeKEY_sv(entry), HEf_SVKEY); else mg_copy((SV*)hv, sv, HeKEY(entry), HeKLEN(entry)); return sv; } } return HeVAL(entry); } /* =for apidoc hv_iternextsv Performs an C, C, and C in one operation. =cut */ SV * Perl_hv_iternextsv(pTHX_ HV *hv, char **key, I32 *retlen) { HE *he; if ( (he = hv_iternext_flags(hv, 0)) == NULL) return NULL; *key = hv_iterkey(he, retlen); return hv_iterval(hv, he); } /* =for apidoc hv_magic Adds magic to a hash. See C. =cut */ void Perl_hv_magic(pTHX_ HV *hv, GV *gv, int how) { sv_magic((SV*)hv, (SV*)gv, how, Nullch, 0); } #if 0 /* use the macro from hv.h instead */ char* Perl_sharepvn(pTHX_ const char *sv, I32 len, U32 hash) { return HEK_KEY(share_hek(sv, len, hash)); } #endif /* possibly free a shared string if no one has access to it * len and hash must both be valid for str. */ void Perl_unsharepvn(pTHX_ const char *str, I32 len, U32 hash) { unshare_hek_or_pvn (NULL, str, len, hash); } void Perl_unshare_hek(pTHX_ HEK *hek) { unshare_hek_or_pvn(hek, NULL, 0, 0); } /* possibly free a shared string if no one has access to it hek if non-NULL takes priority over the other 3, else str, len and hash are used. If so, len and hash must both be valid for str. */ STATIC void S_unshare_hek_or_pvn(pTHX_ HEK *hek, const char *str, I32 len, U32 hash) { register XPVHV* xhv; register HE *entry; register HE **oentry; register I32 i = 1; I32 found = 0; bool is_utf8 = FALSE; int k_flags = 0; const char *save = str; if (hek) { hash = HEK_HASH(hek); } else if (len < 0) { STRLEN tmplen = -len; is_utf8 = TRUE; /* See the note in hv_fetch(). --jhi */ str = (char*)bytes_from_utf8((U8*)str, &tmplen, &is_utf8); len = tmplen; if (is_utf8) k_flags = HVhek_UTF8; if (str != save) k_flags |= HVhek_WASUTF8 | HVhek_FREEKEY; } /* what follows is the moral equivalent of: if ((Svp = hv_fetch(PL_strtab, tmpsv, FALSE, hash))) { if (--*Svp == Nullsv) hv_delete(PL_strtab, str, len, G_DISCARD, hash); } */ xhv = (XPVHV*)SvANY(PL_strtab); /* assert(xhv_array != 0) */ LOCK_STRTAB_MUTEX; /* oentry = &(HvARRAY(hv))[hash & (I32) HvMAX(hv)]; */ oentry = &((HE**)xhv->xhv_array)[hash & (I32) xhv->xhv_max]; if (hek) { for (entry = *oentry; entry; i=0, oentry = &HeNEXT(entry), entry = *oentry) { if (HeKEY_hek(entry) != hek) continue; found = 1; break; } } else { int flags_masked = k_flags & HVhek_MASK; for (entry = *oentry; entry; i=0, oentry = &HeNEXT(entry), entry = *oentry) { if (HeHASH(entry) != hash) /* strings can't be equal */ continue; if (HeKLEN(entry) != len) continue; if (HeKEY(entry) != str && memNE(HeKEY(entry),str,len)) /* is this it? */ continue; if (HeKFLAGS(entry) != flags_masked) continue; found = 1; break; } } if (found) { if (--HeVAL(entry) == Nullsv) { *oentry = HeNEXT(entry); if (i && !*oentry) xhv->xhv_fill--; /* HvFILL(hv)-- */ Safefree(HeKEY_hek(entry)); del_HE(entry); xhv->xhv_keys--; /* HvKEYS(hv)-- */ } } UNLOCK_STRTAB_MUTEX; if (!found && ckWARN_d(WARN_INTERNAL)) Perl_warner(aTHX_ packWARN(WARN_INTERNAL), "Attempt to free non-existent shared string '%s'%s" pTHX__FORMAT, hek ? HEK_KEY(hek) : str, ((k_flags & HVhek_UTF8) ? " (utf8)" : "") pTHX__VALUE); if (k_flags & HVhek_FREEKEY) Safefree(str); } /* get a (constant) string ptr from the global string table * string will get added if it is not already there. * len and hash must both be valid for str. */ HEK * Perl_share_hek(pTHX_ const char *str, I32 len, register U32 hash) { bool is_utf8 = FALSE; int flags = 0; const char *save = str; if (len < 0) { STRLEN tmplen = -len; is_utf8 = TRUE; /* See the note in hv_fetch(). --jhi */ str = (char*)bytes_from_utf8((U8*)str, &tmplen, &is_utf8); len = tmplen; /* If we were able to downgrade here, then than means that we were passed in a key which only had chars 0-255, but was utf8 encoded. */ if (is_utf8) flags = HVhek_UTF8; /* If we found we were able to downgrade the string to bytes, then we should flag that it needs upgrading on keys or each. Also flag that we need share_hek_flags to free the string. */ if (str != save) flags |= HVhek_WASUTF8 | HVhek_FREEKEY; } return share_hek_flags (str, len, hash, flags); } STATIC HEK * S_share_hek_flags(pTHX_ const char *str, I32 len, register U32 hash, int flags) { register XPVHV* xhv; register HE *entry; register HE **oentry; register I32 i = 1; I32 found = 0; int flags_masked = flags & HVhek_MASK; /* what follows is the moral equivalent of: if (!(Svp = hv_fetch(PL_strtab, str, len, FALSE))) hv_store(PL_strtab, str, len, Nullsv, hash); Can't rehash the shared string table, so not sure if it's worth counting the number of entries in the linked list */ xhv = (XPVHV*)SvANY(PL_strtab); /* assert(xhv_array != 0) */ LOCK_STRTAB_MUTEX; /* oentry = &(HvARRAY(hv))[hash & (I32) HvMAX(hv)]; */ oentry = &((HE**)xhv->xhv_array)[hash & (I32) xhv->xhv_max]; for (entry = *oentry; entry; i=0, entry = HeNEXT(entry)) { if (HeHASH(entry) != hash) /* strings can't be equal */ continue; if (HeKLEN(entry) != len) continue; if (HeKEY(entry) != str && memNE(HeKEY(entry),str,len)) /* is this it? */ continue; if (HeKFLAGS(entry) != flags_masked) continue; found = 1; break; } if (!found) { entry = new_HE(); HeKEY_hek(entry) = save_hek_flags(str, len, hash, flags_masked); HeVAL(entry) = Nullsv; HeNEXT(entry) = *oentry; *oentry = entry; xhv->xhv_keys++; /* HvKEYS(hv)++ */ if (i) { /* initial entry? */ xhv->xhv_fill++; /* HvFILL(hv)++ */ } else if (xhv->xhv_keys > (IV)xhv->xhv_max /* HvKEYS(hv) > HvMAX(hv) */) { hsplit(PL_strtab); } } ++HeVAL(entry); /* use value slot as REFCNT */ UNLOCK_STRTAB_MUTEX; if (flags & HVhek_FREEKEY) Safefree(str); return HeKEY_hek(entry); }